Constructive disposition of adjustment of the removable lateral fins in surfboard

ABSTRACT

A fin assembly for adjustably coupling a fin ( 2 ) to a board ( 16 ). The fin assembly includes a fin having a base ( 6 ), the base including a substantially semicircular portion ( 13 ) and a front tip ( 12 ). The fin assembly also includes a fin box ( 1 ) adapted to be attached to a board, the fin box having an opening ( 3 ) for receiving the base of the fin. A rear end of the opening has a substantially semicircular portion ( 5 ) for receiving the semicircular portion of the base. A front end of the opening has a plurality of rifts ( 4 ) for selectively receiving the front tip of the base. Changing the rift that the front tip is disposed in changes an angle of attack of the fin. The fin assembly also includes a fastening assembly ( 7, 8, 9, 10,  and  11 ) for removably securing the fin to the fin box.

FIELD OF THE INVENTION

This detailed description refers to a fin assembly for adjusting a setof lateral fins in a surfboard. The fin assembly allows multiple tuningoptions by means of selectively adjusting a position of a tip of a finto interface with one of a plurality of graduated rifts in a fittingcup, allowing a surfer to adapt the surfboard to his or her own abilityand to the surf, as well as to the marine conditions, without beingcompelled to use different types of boards.

BACKGROUND OF THE INVENTION

The lateral fins are disposed in the base of the surfboard. The lateralfins are typically formed with plastic foam (polyurethane) molded andcovered by a fine layer of polyester resin reinforced with fiber,usually of glass, as has been done since approximately the 1950s. Thelateral fins constitute an important accessory of the surfboard, in viewof the fact that surfers depend on the positioning of the fins and theirdisposition in the surfboard to have greater projection and speed orgreater stability or greater performance during maneuvers. To meet thisneed, different fin fitting techniques and positioning techniques havebeen adopted by others.

In previously developed fin assemblies, the lateral fins are commonlyfixed on the lower part of the board, in numbers of one or more, with acurrent preference of three fins. In previously developed finassemblies, one of four existing methods are used: (i) fastening thefins to the board through resin reinforced with fiber around the base ofthe fins, the “adhesive method”; (ii) the use of a “fin box”, thatallows, theoretically, the removal in cases of damages limited to thefins; (iii) a movable arrangement that allows the fin to be inserted andremoved from a compartment inside of the board; (iv) a movablearrangement that, besides allowing the inserting and removal of thefins, allows the movement of the fin fore and aft within the compartmenton the board.

It happens that each one of those methods still does not permit thesurfer to adjust the fins to the personal and environmentalcircumstances of each case. (i) The adhesive method of adhering the finsto the boards with fiberglass involves considerable costs of manual workto get the required smooth finish and requires the performance ofdifficult and high quality work. The adhesive method also interferes inthe hydrodynamic properties of the fins, results in a decrease in theheight executes of the fin and causes the fixation area to cause waterto be pushed outward from the fixation area, generating turbulences andcavitations. Another great disadvantage in the adhesive method is thatif any damage occurs to the fin, the entire board remains disabled. (ii)When a “fin box” is used, the disadvantage is noted in the large fin boxused during fixation of the fins to the board. The large fin box isexpensive and harmful to the board, for it increases the weight of theboard and the less strong fixation of the fins to the board can harm theperformance and the safety of the fin assembly during use. The advantageregarding fixation by use of a fin box compared to the adhesive methodis that the fin box makes possible the removal of the fins in cases ofsubstitution for repairs or transport. However, this advantage isoutweighed by its complex structure making adoption difficult. (iii)With regard to the moveable arrangement installed inside the board thatallows the more facilitated removal of the fins, although animprovement, doesn't also satisfy the needs of being able to adjust theposition of the fins to the conditions of the sea and skill of the user.(iv) While this technique is the most advanced in the art, i.e., havingthe moveable arrangement accommodation inside the board, because,besides allowing the removal and insertion of the fin, it possesses alongitudinal fitting to receive a member of fixation of the fin throughthe end of the bow or stern in relation to the fin. Although providing anotable advantage to surfers by providing increased stability, thetechnique is still lacking since adjustment of an angle of the fin toreduce drag is not permitted, and it results in cavitations and enlargesthe projection of the fin and decreases performance during maneuvers.

SUMMARY OF THE INVENTION

In order to solve one or more of the mentioned problems, the finassembly of the present invention was developed. The fin assemblyincludes removable lateral fins of a surfboard that, besides permittingthe removability of the lateral fins, may provide the possibility ofremoval of a central fin—when three fins are used. The fin assemblypermits the lateral fins to be adjusted to provide multiple angulartuning options permitting surfers the possibility to adapt the surfboardto their own ability to surf, as well as to the marine conditions,without being compelled to use different types of boards.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present invention becomes perfectly understoodin the following description, which contains references to referencenumbers enclosed in the following figures:

FIG. 1 is a plan view of a fitting cup for receiving a lateral fin,showing an opening having graduated incisions for permitting adjustablefitting of the lateral fin to the fitting cup;

FIG. 2 is an elevation view of the outside face of the fitting cup ofFIG. 1 that it is coupled to the inside of the board;

FIG. 3 is an elevation view of the outside face of the lateral fittingcup of FIG. 1 that it is coupled to the outside of the board;

FIG. 4 is a front elevation view of the outside of the fitting cup ofFIG. 1;

FIG. 5 is a partially exploded elevation view of a lateral fin andfitting cup, showing how the lateral fin interfaces with the fittingcup;

FIG. 6 is a sectional elevation view of the lateral interfaced with thefitting cup;

FIG. 7 is a plan view of the lateral fin interfaced with the fitting cupwith the lateral fin shown in a fitting position wherein a front of thefin is interfaced with a left graduated tuning rift located toward anoutside edge of the surfboard;

FIG. 8 is a plan view of the lateral fin interfaced with the fittingcup, showing a front of the fin base interfaced with a central graduatedtuning rift placing the lateral fin at a central position;

FIG. 9 is a plan view of the lateral fin interfaced with a rightgraduated tuning rift angularly displacing the later fin to the rightrelative to the surfboard;

FIG. 10 is a perspective view of the fitting cup; and

FIG. 11 is a plan view of a tail portion of a surfboard, showing thepositioning of the lateral fins related to the central fin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Regarding the above illustrations, the illustrated embodiment of a finassembly for permitting adjustment of removable lateral fins in asurfboard is shown. The fin assembly includes a surfboard fin (2) havinga base (5) coupled to a fitting cup (1) that includes an opening orincision (3), that possesses in a forward portion graduated rifts (4),which permit the fin to be selectively adjusted to meet the user'sneeds.

The fitting cup (1) is disposed inside the surfboard tail portion (16),and it is produced in plastic or similar material, of equal or superiorlightness and resistance. The fitting cup (1) includes a middle openingor incision (3) having an aft portion (5) which is semicircular in shapeand adapted to adjustably receive a correspondingly shaped posterior tip(13) of the fin's (2) base (6), that is rounded. The fitting cup (1)also includes a front portion disposed in front of the middle opening orincision (3). The front portion includes a plurality of graduated rifts(4) that allow, preferably, the fin (2) to be selectively adjustedbetween three degrees of direction of the fin (2). The fin (2) isfastened by the front tip (12) of the fin's (2) base (6) within one ofthe graduated rifts (4). The front tip (12) of the fin's (2) base (6) ispreferably triangularly shaped and may be selectively interfaced withany one of the three graduated rifts (4) to thereby influence theperformance of the surfboard. The graduated positioning of the fin's (2)base (6) front tip (12) to the fitting cup's (1) graduated rifts (4)happens with assistance by the bearings of the fin's (2) base (6)posterior tip (13) rotating within the semi-circular shaped aft portion(5) of the fitting cup's (1) back tip.

The fin (2) is adjustably coupled to the fitting cup (1) by the fixationof an edge (7) that extends laterally outward from the fin's (2) base(6) into a void accommodation space (8) of the fitting cup (10). Theedge (7) is secured within the void accommodation space (8) through aflat head screw (9) that slides within a slot (10) disposed in thelateral edge (7) and that attaches to a threaded hole (11) disposed inthe center fitting cup (1), close to the inside lateral face of theopening or incision (3). There is a small parallelepiped projection (15)centered longitudinally along the vertical inside lateral face so as tobe positioned laterally between the middle opening or incision (3) andthe edge's (7) void accommodation space (8) and adjacent the smallthreaded hole (11). The projection (15) aids in the fitting of the fin's(2) base (6) within the fitting cup (10) and is received by acorrespondingly shaped recess (14) of the fin's (2) base (6).

The illustrated embodiment of the fin assembly permits the adjustment ofthe removable lateral fins in a surfboard in a totally efficient andpractical way for several types of user applications that require anaccurate, secure, and versatile manner of coupling multiple surfboardlateral fins (2) to a surfboard while permitting tuning of the attackangles of the lateral fins (2) by the manual adjustment of the lateralfins (2) to the fitting cup (1) in the surfboard by the surfer beforethe practice of the sport.

1. A fin assembly for adjustably coupling a fin to a board used forsupporting a user upon a fluid during motion, the fin assemblycomprising: (a) a fin having a base, the base including a substantiallysemicircular portion and a front tip; (b) a fin box adapted to beattached to a board, the fin box having an opening for receiving thebase of the fin, wherein a rear end of the opening has a substantiallysemicircular portion for receiving the semicircular portion of the baseand wherein a front end of the opening has a plurality of rifts, whereinthe front tip of the base is adapted to be selectively disposed in oneof the plurality of rifts, and wherein changing the rift that the fronttip is disposed in changes an angle of the fin with respect to alongitudinal axis of the board; and (c) a fastening assembly forremovably securing the fin to the fin box.
 2. The fin assembly of claim1, wherein the fin includes a lateral edge extending outward from thebase of the fin, and wherein the fastening assembly includes a fastenerfor coupling the lateral edge to the fin box.
 3. The fin assembly ofclaim 2, wherein the lateral edge includes a hole and the fin boxincludes a corresponding hole, and wherein the fastener is adapted tosecure the fin to the fin box by the fastener passing through the holes.4. The fin assembly of claim 1, wherein the lateral edge is semicircularin shape.
 5. The fin assembly of claim 1, wherein the fin box includes aprojection configured to be received within a recess disposed on thebase of the fin when the fin is coupled to the fin box.
 6. The finassembly of claim 5, wherein the projection is substantiallyparallelepiped in shape.